This invention relates to disposable diapers to absorb and hold excretion.
Japanese Patent Application Disclosure Gazette No. 1986-41304 discloses a disposable diaper in which the portion of a topsheet corresponding to a crotch area is cut away to form a longitudinal opening serving to receive excretion, and elastic members are attached, but not in a wrapped manner, to the underside of the topsheet at locations slightly spaced outward from opposite side edges of an the opening defined by opposite inner side edges of the topsheet.
In the above-mentioned disposable diaper of the prior art, the elastic members are attached, but not in a wrapped manner, i.e. in exposed manner, to the underside of the topsheet at the locations slightly spaced outward from the respective inner side edges of the topsheet defining the opposite side edges of the opening, probably because it is practically difficult for the conventional equipment for high speed mass-production of disposable diapers to bond the elastic members with adhesive onto the inner side edges of the topsheet in a neat order and, even when such bonding is attempted, adhesive will partially swell out inwardly and be unpleasantly in contact with the wearer's skin. While such swelling out of adhesive could be avoided by wrapping the elastic members with the inner side edges of the topsheet, such wrapping of the elastic members will require further processing of the inner side edges which define the side edges of the opening and, even after such processing has been done, it will be difficult for the conventional equipment to achieve rapid bonding and wrapping of the elastic members along the inner side edges thus further processed.
It should be noted here that, so far as the elastic members are attached to the topsheet at the locations spaced outward from the inner side edges of the topsheet and not wrapped by these inner side edges, these inner side edges can never form fine gathers. In view of the fact that these inner side edges should be in contact with the wearer's skin and form effective seals, the desired effect of preventing excretion, particularly fluid excretion from leaking, will be seriously affected by the absence of the fine gathers.
Accordingly, it is a principal object of the invention to provide disposable diapers allowing said problem to be eliminated by providing a pair of separately formed stretchable flaps on both sides of the opening formed in the inner topsheet.